JP3128349B2 - Composite magnetic fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a health material using magnetism, a material for promoting health such as bedding and mats, a filter material for collecting magnetic powder, or an ink which prevents coagulation and improves ink dispersibility. The present invention relates to a composite magnetic fiber which is suitable as a material for a felt pen batting to be held and has excellent handleability.

[0002]

2. Description of the Related Art Conventionally, as an organic fiber into which magnetic particles have been kneaded, a method in which magnetic particles are mixed with a thermoplastic polymer having spinnability and melt-mixed and spun to produce a fiber, is used in dry spinning or wet spinning. A method has been proposed in which magnetic particles are mixed in a slurry form with a stock solution for spinning, and the fiber is formed by spinning (Japanese Patent Laid-Open No. 55-98909, Japanese Utility Model Application Laid-Open No. 54-158).
007, JP-B-64-482).

[0003] However, since these magnetic fibers are single fibers obtained by mixing magnetic particles in a fiber-forming polymer, the magnetic particles are exposed in a convex shape on the surface of the fibers, resulting in extremely poor smoothness. is there.

In order to improve this drawback, a conjugate fiber in which a magnetic layer composed of a polymer containing magnetic particles and a protective layer composed of a fiber-forming polymer are composited has been proposed (Japanese Patent Laid-Open No. 57-15757). -167416). However, in order to increase the coercive force in this composite fiber, it is necessary to increase the content of the magnetic particles in the magnetic layer to a considerable amount and to increase the ratio of the magnetic layer. There is a drawback that the stretchability is deteriorated and the magnetic layer is exposed on the fiber surface in various steps. In addition, the mechanical performance of the obtained composite fiber may be reduced.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art, namely, the rough surface state of the fiber surface, various processability such as spinning and drawing, and the deterioration of the mechanical properties of the fiber. Another object of the present invention is to provide a composite magnetic fiber which sufficiently exhibits magnetic properties.

[0006]

According to the present invention, there is provided a polymer containing a protective layer component (A) comprising a fiber-forming thermoplastic polymer and magnetic particles in the range of 5 to 85% by weight. The magnetic particles are composed of the layer component (B), and the maximum point of the magnetic particles is 0.1 to 0.5 μm in the particle size distribution curve represented by the weight of the sedimented particles by the centrifugal gravity sedimentation method.
(D1) having a maximum point of 0.8 to
A mixture of particles (D2) in the range of 2.0μ,
This is achieved by providing a composite magnetic fiber characterized in that its weight ratio (D1 / D2) is in the range of 10/90 to 90/10.

[0007] The magnetic particles in the present invention are not particularly limited as long as they are substances that become magnetized by magnetization and do not cause deterioration of melt spinnability. Specific examples include metals such as iron, nickel, and cobalt, alloys containing these, oxides thereof, and ferrite. Among them, intermetallic compounds such as samarium / cobalt magnetic materials and ferrite compounds such as strontium ferrite are preferable because of their high coercive force.

In the particle size distribution curve represented by the weight of the sedimented particles by the centrifugal gravity sedimentation method, the magnetic particles have a maximum point in the range of 0.1 to 0.5 μm, preferably 0.2 to 0.4 μm.
particles (D1) in the range of μ, and the maximum point is 0.8 to
A mixture of particles (D2) in the range of 2.0μ, preferably in the range of 1.0 to 1.8μ, and D1 and D2
Should be in the range of 10/90 to 90/10, preferably in the range of 20/80 to 80/20. Fibers having higher magnetic performance can be obtained due to the synergistic effect of allowing the particles D1 to add a high concentration of magnetic particles to impart high magnetic performance and increasing the magnetic flux density per unit volume in the particles D2. In the polymer containing magnetic particles whose maximum point of the particle size distribution curve is out of the range specified in the present invention, the dispersibility of the particles becomes poor, and the spinning process or the breaking process frequently causes breakage of single fibers or single fibers, The object of the present invention cannot be achieved. Further, when the mixing weight ratio of the particles D1 and the particles D2 is less than 10/90, the high magnetic performance by the particles D1 is insufficient, and the mixing weight ratio of the particles D1 and the particles D2 exceeds 90/10. In this case, the increase in the magnetic flux density by the particles D2 becomes insufficient.

The content of the magnetic particles in the polymer layer component (B) is in the range of 5 to 85% by weight, preferably in the range of 10 to 70% by weight. When the content is less than 5% by weight, the magnetic performance is insufficient. When the content exceeds 85% by weight, not only does the magnetic performance level off, but also there is a problem in processability such as spinnability.

The polymer constituting the polymer layer component (B)
It is preferable that each processability such as fluidity, spinnability and stretchability is good even if a large amount of magnetic particles are contained.
Specifically, a polyamide-based polymer containing nylon-6, nylon-66, nylon-6,10, nylon-12, nylon-11, nylon-4, nylon-4,6 or the like as a main component, styrene-butadiene A hydrogenated product of a block copolymer of styrene (SBS), a hydrogenated product of a block copolymer of styrene-isoprene-styrene (SIS), and a block copolymer of α-methylstyrene-isoprene-α-methylstyrene. A hydrogenated product of a block copolymer composed of an aromatic vinyl block unit and a conjugated diene block unit such as a hydrogenated product is exemplified.

The polymer constituting the polymer layer component (B)
Various methods are possible for uniformly dispersing and adding the magnetic particles therein. For example, there is a method in which the polymer and the magnetic particles are kneaded and formed by a twin-screw kneading extruder or the like to produce a high-concentration master batch, and the master batch is diluted with the polymer so as to have a predetermined concentration during spinning. In the case of kneading the polymer constituting the polymer layer component (B) and the magnetic particles, the dispersibility of the magnetic particles is improved by adding various dispersing aids. In addition, various antioxidants, stabilizers, lubricants, fluorescent bleaches, coloring agents, pigments, and the like can be contained as necessary.

The polymer constituting the protective layer component (A) includes nylon-6, nylon-66, nylon-6, and nylon-6.
10, nylon-12, nylon-11, nylon-
4, polyamides such as nylon-4,6, polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyhexamethylene terephthalate, and polyolefins such as polyethylene and polypropylene. In terms of practical performance, polyester-based polymers and polyamide-based polymers are particularly preferred. Among them, polyester polymers are more preferable in view of spinnability, processability, and fiber mechanical properties. Examples of polyester-based polymers include terephthalic acid, isophthalic acid, and naphthalene.
Aromatic dicarboxylic acids such as 2,6-dicarboxylic acid, phthalic acid, 4,4′-dicarboxydiphenyl, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid,
An aliphatic dicarboxylic acid such as sebacic acid, or an ester thereof, and ethylene glycol or diethylene glycol;
1,4-butanediol, 1,6-hexanediol-
1,8-octanediol, 1,9-nonandio-
, Neopentyl glycol, cyclohexane-1,4
-Fiber forming properties synthesized from dimethanol, alkylene oxide adducts of bisphenol A, diols such as polyethylene glycol and polytetramethylene glycol, and oxycarboxylic acids such as p-oxybenzoic acid. Can be used, and 80 mol% of the constituent units can be used.
Most preferably, a polyester in which 90 mol% or more is an ethylene terephthalate unit or a butylene terephthalate unit is most preferable.
The components may be copolymerized. The above-mentioned polymer may contain various antioxidants, stabilizers, lubricants, fluorescent bleaches, coloring agents, pigments and the like, if necessary.

The composite fiber of the present invention is composite-spun with a polymer layer component (B) containing magnetic particles and a protective layer component (A), and has a cross section (fiber cross section) perpendicular to the fiber axis of the fiber. The shape is preferably such that the protective layer component (A) occupies 60% or more of the circumference of the fiber surface. If the fiber surface circumference occupied by the protective layer component (A) is less than 60%, the proportion of the polymer layer component (B) exposed on the fiber surface increases, and the fiber layer is formed in a fiber-forming step during yarn production and in post-processing during weaving. , Guides, rollers and the like become severely worn, and furthermore, troubles such as thread breakage occur, which is not preferable.

The protective layer component (A) and the polymer layer component (B)
There are various types of composite forms, and FIGS. 1 to 8 are typical composite forms. Figure 1 is a single core,
2 is a three-core, FIG. 3 is a four-core core-sheath structure fiber cross section, FIG. 4 is a three-layer concentric circle, FIGS. 5 and 6 are partially exposed core-sheath structure fiber cross-sections, and FIGS. It is a composite structure fiber cross section. Depending on the combination of the protective layer component (A) and the polymer layer component (B), in the fiber having the fiber cross-sectional structure shown in FIGS. 7 and 8, peeling may occur at the interface between the components. Fibers having the fiber cross-sectional structure shown in FIGS. 5 and 6 may cause abrasion of guides, rollers, and the like in the fiberizing process and post-processing.

From the viewpoint of preventing abrasion and thread breakage of guides, rollers and the like, and preventing separation at the interface between components, the cross-sectional shape of the core completely covered with the sheath (FIG. 1) FIG. 4) is preferred.

The protective layer component (A) and the polymer layer component (B)
15/85 to 85/15 is preferable, and 20/80 to 80/20 is more preferable. When the composite ratio of the protective layer component (A) is less than 15% by weight, the strength of the obtained composite fiber is undesirably reduced. On the other hand, if the composite ratio of the protective layer component (A) exceeds 85% by weight, the intended magnetic effect of the polymer layer component (B) cannot be sufficiently exhibited.

In the fiber of the present invention, the protective layer component (A) and the polymer layer component (B) are melted by heating in separate melting systems.
Each is conveyed to the spinneret by a normal extrusion spinning device,
It is obtained by combining the two components in a desired composite shape before the spinning hole, spinning and winding, or by temporarily storing the spinning original yarn in a can, then drawing and heat-treating. After spinning, a method of directly stretching or a method of winding at a high speed and directly forming a final product is also used. By using a modified cross-section nozzle during spinning, it may have a polygonal shape such as a three to eight-lobe shape, a T shape, or another modified cross-sectional shape. Further, post-processing such as crimping and false twisting can be performed, and even if the higher-order processing results in a shape similar to a polygon such as a pentagon, a hexagon, or the like.

The conjugate fiber of the present invention may be in the form of a continuous filament or a cut staple in a non-crimped state or a crimped state in almost the same manner as ordinary fibers, in the form of yarn, woven fabric, knitted fabric, non-woven fabric or paper leather. And other fibrous structures. When mixed with other fibers, it is possible to use mixed fiber, ply yarn, ply twist, cross weaving, cross knitting, and any other means. The fibrous structure can be subjected to processing such as dyeing and resin processing as required, and can be provided for various uses. Dyeing can be performed in the form of fibers, yarns and fiber structures

As the method for magnetizing the conjugate fiber of the present invention, the aggregate thereof, or the fiber structure using the same, any known method may be used. For example, the fiber or aggregate may be held in a magnetic field. And a method of holding the fiber structure in a magnetic field. In addition, it is possible to magnetize at the time of spinning, and it is also possible to combine demagnetization and magnetization.

[0020]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. The maximum point in the particle size distribution curve of the magnetic particles in the examples was obtained by dispersing the magnetic particles before addition to the polymer in water using a particle size distribution analyzer (CAPA-500, manufactured by HORIBA, Ltd.). Calculated based on the centrifugal sedimentation curve obtained by measuring the sample by the centrifugal gravity sedimentation method. That is, the particle size and the settled particle weight were determined from the particle size distribution curve based on the centrifugal settling curve. Further, the strength and elongation of the fiber were determined by measuring according to JIS L 1013.

Example 1 Particle D1 having a maximum point of 0.3 μm, particle D2 having a maximum point of 1.5 μm, particle D1 / particle D2 (weight ratio) was 60 /
7 strontium ferrite with a particle size distribution of 40
Nylon-6 (F-70, manufactured by Idemitsu Petrochemical Co., Ltd.) containing 0% by weight was kneaded and extruded with a twin-screw kneader at a temperature of 260 ° C., and the extruded strand was cut into pellets [ Polymer layer component (B)]. On the other hand, polyethylene terephthalate having an intrinsic viscosity [η] = 0.68 was used as the protective layer component (A), and the protective layer component (A) and the polymer component (B) were supplied to separate extruders. It is melted and extruded, and the protective layer component (A) and the polymer component (B) are cored (FIG. 1: composite ratio A / B = 4/1) while being metered in a fixed amount, respectively, and supplied to the nozzle die. , Temperature 300 ℃
, And wound at a speed of 1500 m / min.

The obtained spun yarn is heated at a temperature of 80 ° C.
After pre-heating with a liner, the film was stretched to a stretching ratio of 2.5 times, and then heat-set on a hot plate heated to a temperature of 140 ° C.
A multifilament of 0 denier and 24 filaments was obtained. The stretched yarn has a strength of 3.7 g / denier and an elongation of 3
It was 3.4%.

Using this drawn yarn, a plain woven fabric is produced at a woven density of a warp density of 75 yarns / inch and a weft density of 50 yarns / inch.
A scouring finish was performed. The spinnability, stretchability, processability of fabric production, etc. were all good. The knitted product and the plain fabric obtained by circularly knitting the drawn yarn thus obtained were heated and cooled at 220 ° C. for 20 minutes in a magnetic field of 20,000 Oe (Oersted). The knitted and plain woven fabrics had permanent magnetism and exhibited strong adsorption to iron.

Example 2 A multifilament drawn yarn was obtained in the same manner as in Example 1.
Next, the drawn yarns were drawn together, made into a 100,000-denier tow, crimped by a crimping machine, and then cut to obtain short fibers. The short fibers are made into a web through a card, the obtained webs are laminated and subjected to needle punching, and then heat-treated in an oven at a temperature of 250 ° C. to obtain a nonwoven fabric having a basis weight of 200 g / m 2. Was. The shape retention of the nonwoven fabric was good.

When the nonwoven fabric was magnetized in a magnetic field of 10,000 Oe (Oersted), the nonwoven fabric exhibited strong permanent magnetism. When iron powder having a particle size of 0.3 to 10 μm was uniformly sprayed on the nonwoven fabric and the air was applied to observe the state of adsorption of the iron powder, the iron powder was almost strongly adsorbed to the nonwoven fabric.

Example 3 Kneading, spinning, stretching, weaving and knitting of a cylinder in the same manner as in Example 1 except that a hydrogenated product of SIS (Septon KL2002, manufactured by Kuraray Co., Ltd.) was used instead of nylon-6. Then, a nonwoven fabric was prepared, magnetized, and evaluated for magnetic performance. The woven fabric, knitted fabric and non-woven fabric have strong permanent magnetism and exhibited strong adsorption to all iron powders having a particle size of 0.3 to 10 µm.

Comparative Examples 1 to 3 In Example 1, instead of strontium ferrite, only strontium ferrite having a maximum point of 1.1 μm (Comparative Example 1) and only strontium ferrite having a maximum point of 0.3 μm (Comparative Example) 2) Kneading, spinning, stretching, weaving, knitting of a cylinder, and the like, except that only strontium ferrite having a maximum point of 1.5 μm (Comparative Example 3) was used.
A nonwoven fabric was prepared, magnetized, and evaluated for magnetic performance. Compared to the woven fabric, knitted fabric, and nonwoven fabric obtained in Examples 1 to 3, the permanent magnetism was low, and a part of the iron powder scattered on the nonwoven fabric was observed to be scattered when exposed to wind. .

[0028]

The composite spinning of a polymer layer component containing a large amount of magnetic particles having a specific particle size distribution and a protective layer component made of a fiber-forming thermoplastic polymer,
A magnetic fiber having very excellent magnetic performance and excellent spinnability and fiber mechanical properties can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a cross-sectional shape of a conjugate fiber of the present invention.

FIG. 2 is a view showing another example of the cross-sectional shape of the conjugate fiber of the present invention.

FIG. 3 is a diagram showing another example of the cross-sectional shape of the conjugate fiber of the present invention.

FIG. 4 is a diagram showing another example of the cross-sectional shape of the conjugate fiber of the present invention.

FIG. 5 is a diagram showing another example of the cross-sectional shape of the conjugate fiber of the present invention.

FIG. 6 is a view showing another example of the cross-sectional shape of the conjugate fiber of the present invention.

FIG. 7 is a view showing another example of the cross-sectional shape of the conjugate fiber of the present invention.

FIG. 8 is a diagram showing another example of the cross-sectional shape of the conjugate fiber of the present invention.

[Explanation of symbols]

 A Protective layer component composed of a fiber-forming thermoplastic polymer B Polymer layer component containing magnetic particles

Continuation of the front page (56) References JP-A-55-98909 (JP, A) JP-A-57-167416 (JP, A) JP-A-57-173312 (JP, A) JP-A-4-119141 (JP) JP-A-4-128413 (JP, A) JP-A-3-130413 (JP, A) JP-A-54-158007 (JP, U) JP-B-64-482 (JP, B2) (58) Field surveyed (Int.Cl. ⁷ , DB name) D01F 8/04 D01F 1/10

Claims (1)

(57) [Claims] The present invention comprises a protective layer component (A) comprising a fiber-forming thermoplastic polymer and a polymer layer component (B) containing magnetic particles in a range of 5 to 85% by weight. In the particle size distribution curve represented by the weight of the sedimented particles by the centrifugal gravity sedimentation method, the maximum point is 0.1 to 0.1.
Particles (D1) in the range of 5μ and a maximum point of 0.8
A mixture of particles (D2) in the range of ２．０2.0 μm, wherein the weight ratio (D1 / D2) is 10 / 90-90 / 1.
A composite magnetic fiber having a range of 0.